Repozytorium Uniwersytetu Śląskiego RE-BUŚ
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Ocena zastosowania flotacji w odzysku metali z rozdrobnionych płyt obwodów drukowanych
No full textThe paper presents an assessment of flotation efficiency in the separation of plastics from metals derived from printed circuit boards (PCBs). The PCBs were ground in a knife mill prior to flotation. The contact angles of various materials corresponding to the grains from ground PCBs were measured, and a series of flotation tests was carried out to obtain the best product. The impact of the following parameters were investigated: the reagent and its dose, the airflow rate through the flotation tank and the feed concentration. The highest efficiency of metal recovery from PCBs was achieved for Dimethoxy dipropyleneglycol at a concentration of 157 mg/dm3 and with an airflow of 200 dm3/h and a feed concentration of <50 g/dm3. In the hydrophilic product (concentrate), it was mainly Cu (40%) and Sn (7.8%) that were identified by means of XRF, but there were also trace amounts of precious metals such as Au (0.024%), Ag (0.5797%) and Pd (149 ppm). Impurities in the form of Si (5%), Ca (3.2) and Br (2.1) were also identified in this product. Small amounts of metals in their metallic form were identified in the hydrophobic product (waste), mainly Cu (2.3), Al (1.7) and Sn (1.1). As a result of the research, high recovery ratios were obtained for Cu (93%), Sn (84), Ag (83) and Au (69). The purity of obtained metal concentrate with this method was lower in comparison with the other methods of the recovery of metals from ground PCBs for the same feed, i.e. electrostatic or gravity separation. Also considering other factors such as the environmental impact of the flotation process, the number of facilities and their energy consumption, this process should not be used in the developed metal recovery technology. Using electrostatic separation for the same feed obtained much better results
Intrusion and extrusion of liquids in highly confining media: bridging fundamental research to applications
No full textWetting and drying of pores or cavities, made by walls that attract or repel the liquid, is a ubiquitous process in nature and has many technological applications including, for example, liquid separation, chromatography, energy damping, conversion, and storage. Understanding under which conditions intrusion/extrusion takes place and how to control/tune them by chemical or physical means are currently among the main questions in the field. Historically, the theory to model intrusion/extrusion was based on the mechanics of fluids. However, the discovery of the existence of metastable states, where systems are kinetically trapped in the intruded or extruded configuration, fostered the research based on modern statistical mechanics concepts and more accurate models of the liquid, vapor, and gas phases beyond the simplest sharp interface representation. In parallel, inspired by the growing number of technological applications of intrusion/extrusion, experimental research blossomed considering systems with complex chemistry and pore topology, possessing flexible frameworks, and presenting unusual properties, such as negative volumetric compressibility. In this article, we review recent theoretical and experimental progresses, presenting it in the context of unifying framework. We illustrate also emerging technological applications of intrusion/extrusion and discuss challenges ahead
Ocena wiedzy klientek salonów kosmetycznych na temat zabiegów z wykorzystaniem kwasu hialuronowego i ich wpływu na rewitalizację skóry
No full textSkin aging is a natural, physiological and inevitable process.
Today, many women strive to keep their young appearance as
long as possible. The knowledge of women about the factors
accelerating or slowing down the aging process of the skin is
growing. Hyaluronic acid is a substance widely used in modern
cosmetology and is one of the most valued on the aesthetic
market due to its high biocompatibility and low toxicity. It ma-
intains proper hydration, a healthy and youthful appearance
of the skin. It occurs naturally in the human body and other
living organisms and it is a crucial element of both cosmetic
and aesthetic medicine treatments. Hyaluronic acid is a com-
ponent of cosmetics used externally in preparations intended
for home care. Therapies with HA support the counteraction
against such skin defects as wrinkles, dry skin, loss of skin ela-
sticity and firmness, scars, stretch marks, cellulite, burns, and
wounds. Women are aware of the effects of hyaluronic acid on
the skin. The aim of this study was to examine the knowled-
ge of clients of beauty salons about treatments with the use
of hyaluronic acid and their impact on skin revitalization. The
study was achieved by conducting a proprietary questionnaire
checking the knowledge of female respondents about hyalu-
ronic acid and its use in anti-aging therapy. By analyzing the
obtained results, it can be concluded that women have basic
knowledge of hyaluronic acid
Cenospheres-Reinforced PA-12 Composite: Preparation, Physicochemical Properties, and Soaking Tests
No full textThe main aim of this research was the preparation of a polymer–ceramic composite with
PA-12 as the polymer matrix and modified aluminosilicate cenospheres (CSs) as the ceramic filler. The
CSs were subjected to an early purification and cleaning process, which was also taken as a second
objective. The CSs were surface modified by a two-step process: (1) etching in Piranha solution
and (2) silanization in 3-aminopropyltriethoxysilane. The composite was made for 3D printing by
FDM. Raw and modified CSs and a composite with PA-12 were subjected to the following tests:
surface development including pores (BET), real density (HP), chemical composition and morphology
(SEM/EDS, FTIR), grain analysis (PSD), phase composition (XRD), hardness (HV), and static tensile
tests. The composites were subjected to soaking under simulated body fluid (SBF) conditions in
artificial saliva for 14, 21, and 29 days. Compared to pure PA-12, PA-12_CS had generally better
mechanical properties and was more resistant to SBF at elevated temperatures and soaking times.
These results showed this material has potential for use in biomedical applications. These results also
showed the necessity of developing a kinetic aging model for aging in different liquids to verify the
true value of this material
Modeling of Nitrification Kinetics in a Respirometric Biosensor under Suboptimal Conditions
No full textSensitive detection with cell biosensors requires optimization of their working conditions
and standardization of the response in variable physicochemical conditions. The introduction of an
analyte to a sensor, which contributes to this variability, may account for the modeling of microbial
metabolism. We constructed a multiparameter model of a water toxicity sensor of Automatic Biodetector
forWater Toxicity (ABTOW), developed by our group and based on nitrifying bacteria. The
model describes the kinetics of nitrification as a function of four orthogonal parameters: temperature,
pH, oxygen and ammonium concentration. Furthermore, we characterized the signal-to-noise ratio
(SNR) of the ABTOW readout as a function of these parameters. Thus, a region of parameter space
corresponding to optimal ABTOW operation is identified and its sensitivity quantified. We applied
the model to describe the ABTOW performance in non-equilibrium conditions produced by rapid
changes in pH and temperature. In sum, the model based on four physicochemical parameters
describes changes in the biosensor’s activity, the biological element of which are nitrifying bacteria
characterized by simple chemolithoautotrophic metabolism. The description of reaction kinetics
through multiparameter modeling in combination with stability analysis can find application in
process control in biotechnology, biodetection and environmental research
New D−π–D−π–A Systems Based on Phenothiazine Derivatives with Imidazole Structures for Photovoltaics
No full textTwo new compounds with an N-octyl phenothia-zine core substituted at C(7) position via a triple bond with imidazole-containing butyl or dodecyl chains bearing on the opposite side at the C(7) cyanoacrylate moiety were synthesized. Photophysical and electrochemical studies were performed to evaluate the possibility of applying them in the dye-sensitized solar cells (DSSCs). The investigations were supported by density functional theory and time-dependent DFT. The synthesized dyes showed a similar absorption profile ranging from 250 to 600 nm in solvents and a high value of light-harvesting efficiency of about 0.8. It was found that its photoluminescence quantum yield was solvent-dependent, and the highest value (about 50%) was reached in DMF solution. Electrochemical measurements revealed that both compounds showed electron injection ability from the LUMO of the molecule to the TiO2 conduction band and the possibility of regeneration by an electrolyte. DSSCs sensitized with the phenothiazine derivatives differing in TiO2 thickness and the type of electrolyte (iodide and cobalt) were prepared. Additionally, transient absorption measurements in solution and solar cells were carried out to study excited-state properties and electron transfer dynamics. The influence of the hydrophobic hydrocarbon chain length of the imidazole unit in these dyes as well as TiO2 thickness and the type of electrolyte on the device performance was observed. DSSCs sensitized with phenothiazine with dodecyl chains showed higher photocurrent, open-circuit voltage, and finally the power conversion efficiency, regardless of TiO2 thickness
Post-Extraction Novel Ecosystems Support Plant and Vegetation Diversity in Urban-Industrial Landscapes
No full textLong-term exploitation of mineral resources has significantly changed the natural environment
in urban-industrial landscapes. The changes on the surface of the extraction sites as a
consequence of excavation of mineral resources provide specific mineral oligotrophic habitats on
which plant species and thus vegetation can establish spontaneously. Some of these sites fulfill the
prerequisites of novel ecosystems. This study was conducted on the spontaneous vegetation of
post-extraction sites. Lists of species spontaneously covering these sites were prepared based on
published data and our own records. This research revealed that species composition and vegetation
types vary in time. These post-extraction novel ecosystems are also important for the presence of
rare, endangered, and protected species noted in patches of different vegetation types. The variety of
habitat conditions provided by these sites facilitates the occurrence of a wide spectrum of plants (both
in terms of their socio-ecological origin and their ecological spectrum). This research proves how
important these post-extraction novel ecosystems are for supporting plant and vegetation diversity
in urban-industrial landscapes. Enhancing the biodiversity significantly increases the ecosystem
services delivered by these sites and also the functioning of entire ecosystems. These natural processes
on human habitats are essential in urban-industrial ecosystem landscape mosaics
Characterization of Catechol-1,2-Dioxygenase (Acdo1p) From Blastobotrys raffinosifermentans and Investigation of Its Role in the Catabolism of Aromatic Compounds
No full textGallic acid, protocatechuic acid, catechol, and pyrogallol are only a few examples of industrially relevant aromatics. Today much attention is paid to the development of new microbial factories for the environmentally friendly biosynthesis of industrially relevant chemicals with renewable resources or organic pollutants as the starting material. The non–conventional yeast, Blastobotrys raffinosifermentans, possesses attractive properties for industrial bio-production processes such as thermo- and osmotolerance. An additional advantage is its broad substrate spectrum, with tannins at the forefront. The present study is dedicated to the characterization of catechol-1,2-dioxygenase (Acdo1p) and the analysis of its function in B. raffinosifermentans tannic acid catabolism. Acdo1p is a dimeric protein with higher affinity for catechol (KM = 0.004 ± 0.001 mM, kcat = 15.6 ± 0.4 s–1) than to pyrogallol (KM = 0.1 ± 0.02 mM, kcat = 10.6 ± 0.4 s–1). It is an intradiol dioxygenase and its reaction product with catechol as the substrate is cis,cis-muconic acid. B. raffinosifermentans G1212/YIC102-AYNI1-ACDO1-6H, which expresses the ACDO1 gene under the control of the strong nitrate-inducible AYNI1 promoter, achieved a maximum catechol-1,2-dioxygenase activity of 280.6 U/L and 26.9 U/g of dry cell weight in yeast grown in minimal medium with nitrate as the nitrogen source and 1.5% glucose as the carbon source. In the same medium with glucose as the carbon source, catechol-1,2-dioxygenase activity was not detected for the control strain G1212/YIC102 with ACDO1 expression under the regulation of its respective endogenous promoter. Gene expression analysis showed that ACDO1 is induced by gallic acid and protocatechuic acid. In contrast to the wild-type strain, the B. raffinosifermentans strain with a deletion of the ACDO1 gene was unable to grow on medium supplemented with gallic acid or protocatechuic acid as the sole carbon source. In summary, we propose that due to its substrate specificity, its thermal stability, and its ability to undergo long-term storage without significant loss of activity, B. raffinosifermentans catechol-1,2-dioxygenase (Acdo1p) is a promising enzyme candidate for industrial applications
Sekcja Briologiczna (1978)
No full text"Sekcja Briologiczna jest jedną z krócej działających sekcji PTB. Oficjalne zgłoszenie do Zarządu
Głównego PTB w sprawie utworzenia Sekcji wystosowała jesienią 1978 r. prof. Irena Rejment-
Grochowska (Uniwersytet Warszawski). Była to realizacja uchwały podjętej przez uczestników
Krajowego Sympozjum Briologicznego, które odbyło się w dniach 21–23 września 1978 r. w Porąbce-
Kozubniku z inicjatywy prof. Krzysztofa Rostańskiego (Uniwersytet Śląski) (Ryc. 11.9.1). W efekcie
tych działań na zebraniu Zarządu Głównego PTB w dniu 9 grudnia 1978 r. powołana została Sekcja
Briologiczna. Liczba członków w dniu założenia wynosiła 25, a pierwszą przewodniczącą została
prof. Irena Rejment-Grochowska. Niestety, nie zdążyła wypracować formy działania utworzonej
przez siebie Sekcji, bo nieoczekiwanie zmarła pół roku później, 6 maja 1979 roku. Jej obowiązki
przejął prof. Jerzy Szweykowski." [...] (fragm.
Magnetodielectric and low-frequency microwave absorption properties of entropy stabilised ferrites and 3D printed composites
No full textHigh-entropy ferrites (HEFs) are a new group of high-entropy oxides with unique magnetodielectric properties
that offer a wide array of possibilities for high-frequency applications. Various ions were introduced at octahedral
sites in the spinel structure to test the role of the high-entropy structure’s formation on its properties. The
structural analysis confirmed the formation of single-phase spinel structure even for (FeCoNiMg)(FeCr)2O4 HEF.
Dielectric studies showed that introducing Mg2+ and Cr3+ ions increased electrical conductivity and dielectric
losses over a wide frequency range. Low frequency (from 0.8 to 1.5 GHz) studies showed that for (FeCo)Fe2O4
and (FeCoNi)Fe2O4 ferrites reflection losses (RL) are negligible, while for both (FeCoNiMg)Fe2O4 and (FeCoNiMg)(
FeCr)2O4 ferrites RL higher than 90% were observed. The temperature dependence on the absorption
properties was confirmed for (FeCoNiMg)(FeCr)2O4 HEF. The highest absorption window was observed for 343
K, for which RL higher than 90% appears from 1.25 to 1.5 GHz. The possibility of the 3D printing of microwave
absorption composites from HEFs was also tested. It was confirmed that the addition of (FeCoNiMg)(FeCr)2O4
HEF drastically increases the absorption properties up to 85.5% at 2.72 GHz for the absorber with the same
thickness as made from the pure acrylonitrile butadiene styrene (ABS). Interestingly, the EMI shielding properties
of these composites are mainly related to the dielectric losses improved by the addition of entropy stabilised
ferrites in 3D printed composites with various ferrite concentrations